Project Summary/Abstract Despite intensive focus and advances in understanding the genetics of Rett syndrome (RTT), there remains a strikingly absent evidence base to guide applied interventions targeting communication. Our long- term goals are to develop best practices for improvement in communication outcomes and quality of life in individuals with RTT and other similar disorders and to overcome barriers to service delivery. The objectives of this application are to develop a model of reinforcement-based intervention for improving the communicative outcomes and indicators of quality of life for girls and women with RTT, and to broaden our impact through the use of telepresence to reach a larger number of girls and women than would otherwise be feasible. Through findings from our preliminary research, these objectives operate from the central hypothesis that girls and women with RTT have the capacity to communicate, and that they will use idiosyncratic behaviors to communicate in the absence of systematic intervention. We plan to test this central hypothesis through the following two specific aims: (1) to develop a reinforcement-based intervention model that addresses the complex communicative needs in RTT and (2) to evaluate telepresence as an innovative service delivery mechanism for supporting/delivering communication intervention in RTT. We will address these aims through rigorous within-subject experimental designs and group statistical analysis of a three-phase analysis and intervention sequence with at least 24 girls and women with RTT. Our study will contribute evidence-based communication intervention guidelines for individuals with RTT by setting a standard of care for individuals with RTT and related complex communication needs, it will lay the foundational scientific understanding of the efficacy of reinforcement-based intervention with this population and others with complex communication needs, and it will demonstrate the effective use of telepresence which will vastly expand capacity to deliver effective care (nationally, internationally) for communication needs to individuals affected by RTT and their families. Our proposal is innovative, in our opinion, because it rejects the supposition that individuals with RTT do not possess the developmental level necessary to acquire intentional communication skills and instead, uses telepresence as a vehicle for reaching families affected by RTT to provide reinforcement-based intervention to develop communication skills and, in turn, improve quality of life.